54 Gene expression in retinal development, the CRX and NRL stories Leber congenital amaurosis and the CRX gene product. Recessive NRL mutations in patients with clumped pigmentary retinal degeneration and relative preservation of blue cone function Koji M. Nishiguchi*, James S. Friedman†, Michael A. Sandberg‡, Anand Swaroop†§, Eliot L. Berson‡, and Thaddeus P. Dryja*¶